Atmosphere
The atmosphere is a blanket of air which surrounds the Earth. It reaches over 560km from the surface of the planet. We are only able to see what occurs fairly close to the ground. Early attempts at studying the nature of the atmosphere used clues from the weather, the beautiful multi-colored sunsets and sunrises, and the twinkling of stars. With the use of sensitive instruments from space, we are able to get a better view of the functioning of the atmosphere. Life on Earth is supported by the atmosphere, solar energy, and our planet's magnetic fields. The atmosphere absorbs the energy from the Sun, recycles water and other chemicals, and works with the electrical and magnetic forces to provide a moderate climate. The atmosphere also protects us from high-energy radiation and the frigid vacuum of space. The envelope of gas surrounding the Earth changes from the ground up. Four distinct layers have been identified using thermal characteristics (temperature changes), chemical composition, movement and density. Troposphere The troposphere starts at the Earth's surface and extends 8km - 14.5km high. This part of the atmosphere is the most dense. As you climb higher in this layer, the temperature drops from about 17 degrees to -52 degrees Celsius. Almost all weather is in this region. The tropopause sepearates the troposphere from the next layer. The tropopause and the troposphere are known as the lower atmosphere. Stratosphere The stratosphere starts just above the troposphere and extends to 50km high. Compared to the troposphere, this part of the atmosphere is dry and less dense. The temperature in this region increases gradually to -3 degrees Celsius, due to the absorbtion of ultraviolet radiation. The ozone layer, which absorbs and scatters the solar ultraviolet radiation, is in this layer. Ninety-nine percent of air is located in the troposphere and stratosphere. The stratopause separates the stratosphere from the next layer. Mesosphere The mesosphere starts just above the stratosphere and extends to 85km high. In this region, the temperatures again fall as low as -93 degrees Celsius as you increase in altitude. The chemicals are in an excited state, as they absorb energy from the Sun. The mesopause separates the mesosphere from the thermosphere. The regions of the stratosphere and mesosphere, along with the stratopause and mesopause, are called the middle atmosphere. Thermosphere The thermosphere starts just above the mesosphere and extends to 600km high. The temperatures go up as you increase in altitude due to the Sun's energy. Temperatures in this region can go as high as 1,727 degrees Celsius. Chemical reactions occur much faster here than on the surface of the Earth. This layer is known as the upper atmosphere. la la la la, la la la la, elmos world. this is gay Atmospheric Composition The atmosphere of Earth is primarily composed of Nitrogen, Oxygen and Argon. A myriad of other very influential components are also present which include the water, greenhouse gases (Ozone) and Carbon Dioxide. Beyond the Atmosphere The exosphere starts at the top of the thermosphere and continues until it merges with interplanetary gases, or space. In this region of the atmosphere, Hydrogen and Helium are the prime components and are only present at extremely low densities. de:Atmosphäre